Method of treating fibrous material



Patented Oc t. 27, 1 931 PATENT OFFICE mun. eoomun. on NEW YORK, n. Y.

METHOD OF TREATING FIBROUS MATERIAL No Drawing. Application filed April7,

v The present invention relates generally to improvements in methods oftreating vegetable fibrous material, especially that kind prepared fromor having the characteristics 3 of the oriental plants mitzumata, kodzu,gampi or other similar plants, with a soluble cellulose derivative, andhas particular reference to a method which involves the treatment ofsaid material with a soluble'cellu-' 19 lose derivative which issubsequently converted into an insoluble cellulose deposition upon afibrous base.

The method herein described may be employed to prepare materials whichwill serve several useful purposes of varying character. It has beenfound that the general method may be used to preserve, for indefiniteperiods, records which may be printed upon a fibrous base and protectthe records from at- 20 mospheric and climatic changes and also preventthe destruction thereof by any reagents except those which have asolvent action upon the fibrous base or the cellulose. Another functionof the present method and the one which at the present time isconsidered more important and useful is that of the production of amaterial which will afford an excellent and highly efiicient substitutefor the natural gut of animals, such as used for sausage casings.

This material simulates the properties ofthe natural gut, in appearance,tensile strength, elasticity, flexibllity, pl iability and porosity. Ithas also, like the natural gut, the uniqueproperties of expansion whenmoistened and contraction when dried. This material is especiallyadaptable when formed intoa container for the purpose of preparingbolognas, sausage or any other kind of food product for which thenatural gut may be used, and has been found by the most exacting teststo be especially practical where smoking and boiling processes arefollowed. Furthermore, the material excels the natural gut because it ismore sanitary and clean. 7

Many attempts have heretofore been made to produce an artificial casingsimulating in appearance and qualities that of the natural 1980. SerialNo. 442,443,

ening of the tear.

mzlssurn gut, but these attempts have all proven unsuccessful for onereason or another.

It is known that in the prior art the use has been made of what is knownas cellulose hydrate for producing a casing which has its cellularstructure entirely destroyed to render it non-fibrous. However,exhaustive experiments have shown that a practical and workable casingcannot be made under this process mainly for the reason that, without afibrous base, the material, when formed into a tubular container, wouldnot withstand the rigorous tests to which it must be subjected whenfilled with meats by means of compressed air, steam, or hydraulic 1pressure. .The impracticability of this casing lies largely in the factthat it loses most of its tenslle strength when damp or wet. Because ofthis characteristic, even if, by taking great precautions to keep thecasing dry, the tendency to burst could be lessened during the fillingprocess, still the wet meat, which would necessarily wet the casingwould have a tendency to weaken it sufficiently to cause it to fall fromthe racks during the smoking process. Also, in the case of thenon-fibrous material, any imperfections, such as small holes or tears inthe casing, will render the casing useless for filling purposes. This isbecause any force exerted at the. point of imperfection will cause aprogressive enlargement of the hole or a progressive length- On theother hand, the

casing made under the new process, because of its fibrous base, hasincreased tensile strength even when wet. Further, it is because ofthis'fibrous base that the further progress of any break or tear isretarded and its area restricted. The new casing will expand when wetand contract when dry and thus simulates certain desirablecharacteristics inherent in the natural gut casing. Because of thesevarious essential characteris- I tics the meat in the container adheresto the inner surface from the beginning of the treatment until the endfor the reason that ,ifthe meat content should dry and shrink or dam enand expand the casmg will do likewise 1n H a uniform and satisfactorymanner.

The resultant product of this new method is prepared under asepticconditions, will not putresce or decompose, and has been found, by themost exacting tests, to be espec ally useful when prepared in the formof a tubular container for foods intended for human con-' ties ofnatural gut is required.

It has been customary, in the manufacture of bolognas and the like, toimprint a suitable stamp upon the exterior surface of the natural gutcontainer, after filling, or to attach a printed identification tag atone end of the filled container. much deceit and fraud as it is arelatively easy matter for unscrupulous dealers to alter or change anvidentification mark.

This-objection may be overcome by the present method, for the materialproduced there by is a synthetic product and it has been discovered thatan imprintation with ink or the like may be made upon the fibrous baseand beneath the outer layers or surfaces of the finished product, whichimprintation will be as permanent as the material itself.

One of the essential features of the present invention is the treatmentof a vegetable fibrous base with a soluble cellulose, such as a suitableester or ether, a solution of either of which is prepared by dissolvingin nonalkaline or inert organic solvents, which is subsequentlysubjected to a suitable chemical treatment resulting in the partial orcomplete precipitation or regeneration of cellulose to form a-partlysoluable and insoluable or completely insoluble cellulose depositionupon the fibrous base.

Before entering into a description of the various steps involved in thepresent method, it is desired to set forth at some length what isunderstood to be the meaning of the terms. cellulose, soluble celluloseand insoluble cellulose. According to the most recent scientificunderstanding, the general term cellulose means a colloidal materialforming the framework of all vegetable cells; It has the same empiricalformula (C,H O,)n as starch and like the latter belongs to the generalclass of organic bodies known as carbohydrates. Like starch, it may behydro lyzed, though more slowly, to glucose, but,

unlike starch, cellulose occurs as fibres instead of granules, issubstantially unaffected by boiling water and is not stained by iodine.

. 1 Klason (Svensk Papers, Tid. 27 261-4,

1924) suggests that cellulose be defined as a carbohydrate which at 98C. is not soluble in a digesting acid containing 13 grams of wholly freeS0 per liter.

The formation of a soluble cellulose body may be brought about by theresolution of any '65. cellulose material by one of two general Thispractice has led to methods, to wit: (1) by the dispersion of thecellulose through liquid solutions of special chemical reagents, andv(2) by the bringing into solution cellulose esters or ethers by means ofsuitable solvents.

By pursuing the first general method, the following chemical reagentshave been found to bring about the desired results :Schweitzersreagent,Cu-NH,-method; a 40% solution of ZnCl at C.; a .H Cl solutionof Zn inthe cold; H Cl solutions of Sb Cl, (concentrated), SbCh, BiCl and TiCh;also acid solutions of CaCl BaCl LiCl, CaBr,, LiBr and M Br also hotsolutions of thiocyanates %sulfocyanides) as Ca .thiocyanate. The exactmechanism of bringing the cellulose into solution is not very wellunderstood. It

is claimed, however, that whenever the chemical action is allowed-toproceed to a point beyond which there is a degradation of the cellulosemolecule, the colloidal-power of the solution is diminished and, ofcourse, Whenever there-is a degradation of the molecule it will beimpossible to regenerate the original cellulose molecule when thereagents causing the dispersion are removed.

It hasbeen found that, by the union of cellulose with acid or alcoholradicals forming "esters and ethers, if care is taken to avoid kind,nature andamount of the plasticizer used with the ester, thephysicalconstants of thesolvent or solvent combination, the time andtemperature, and whether the viscosity has been artificially diminished.An unmodified cellulose gives a more viscous solution.

The term insoluble cellulose, as used in the present invention, isemployed to indicate the regenerated or recovered cellulose which may beobtained in the case of the firstmentioned method, by the precipitationor the removal of the chemicals causing dispersion, or, in the secondmethod, by the hydroly- I sis. of the ester or the decomposition of thehave no chemical action .on the structure of impregnating avegetablefibrous structure.

with a suitable soluble cellulose derivative andjthen, by suitablemethods, render1ng the soluble derivativeinsoluble. I The lmpregatedfibrous structure may be formed either by impregnating flat sheets offibrous material, or else by mlxing the fibres, in pulp form,

. with the soluble cellulose derivatlve. More specifically, thevegetable fibre used in thepresent invention is prepared from the plantsmitzumata, kodzu, or gampi and other similar plants, which plants growprolifically in the Orient. The fibres of all three of these lants havethe common characteristics of eing thin, long, supple and strong andhave been found especially suitable for carrying out the presentinvention because of their ability to absorb and form a unitaryappearing body with the soluble cellulose derivatives and afterregeneration of the cellulose to form a homogeneous fabric. It will beunderstood, however, that any other fibres having similarcharacteristics may be employed without departing from the spirit orscope of the invention.

Soluble cellulose derivatives may be obtained in various ways, asindicated above. Especially suitable results will be obtained whennormal or .cotton cellulose is used.

In carrying out the invention, the cellulose ester usedmay preferably becellulose acetate. This ester is prepared from purified cotton. Theester is. itself non-toxic and non-inflammable and is brou ht intosolution in the manner indicate below. None of the chemicals ormaterials used in the present method are toxic or injurious to healthand the final resulting product comprising fibrous material, cellulose,or any other suitable finishing agent is not only non-toxic but edible.

Several methods may be fbllowed in obtaining a container for receivingmeats,- but in any case it is essential that in the initial step thecellulose ester be intermingled with the fibrousmaterial, for example:

(1) The fibrous material employed may be cut to suitable dimensions andthen the cut sheets are formed into cylindrical tubes by sealing thelongitudinal edges with a suit-' able-adhesive by sewing or otherwise.

(2) The fibrous material may be impregnated first and the tubes formedafterwards.

- (3) A film of cellulose acetate may in suitable manner be attached tothe fibrous material rior to the formation of a tube, or

(4 It is within the scope of the invention that material be firstreduced to pulp and mixed with theproper solution of cellulose acetateand the whole finally cast into a suitable mold and shaped to form atube or other pregnation, or under certain conditions it may celluloseacetate has dried, but prior to subjecting the ester to furthertreatments. In this connection, it is pointed out that, if the method isto be employed for the preservation of written or printed records, aspreviously suggested, the impri'ntations are preferably made on the flatsheets and the formation of the sheets into tubes is then an unnecessarystep in the operation.

Irrespective of the particular method employed, the ultimate object isto obtain a substantially cylindrical tube of the fibrous baseimpregnated with the soluble cellulose derivative. The resultingimpregnation should give a translucent, non-porous material practicallyunaifected by hot or cold water. Especially satisfactory results areattained by dissolving the acetate in proper solvents and plasticizersuntil the desired viscosity and other desired physical characteristicsare obtained.v In order to save the labor of tying ofi one end of thetube with twine, the resulting impregnated fibrous cylindrical tubemaybe constricted or closed at one end by first softening it with asuitable solvent and then twisting it until a closed nipple form isproduced at this end. The end is then permitted to again dry, thusforming a solid body which does not become untwisted. After completelydrying the impregnated material by allowing the volatile solvents toevaporate, the tube, with or without the form of closure just described,is then subjected to the treatment by a sufliciently concentrated"alkali metal hydroxide as sodium hydroxide,

dissolved in alcohol or other appropriate solvent, until the ester issubstantially completely hydrolyzed, the cellulose remaining .in a moreor less modified form as an insoluble deposition upon the fibrousstructural base,

rendering the resultant material porous and be produced after theimpregnated pr'egnating the base with a solution of cellulose acetate,and then subjecting the impregnation to the action of an alkalinesolution to then subjectin substantially or completely regenerate thecellulose as an insoluble depositlon upon the fibrous base.

3. The method of treating a fibrous base prepared from mitzumata, kodzu,gampi and other similar plants, which comprises impregnating a base witha solution of cellulose acetate prepared by dissolying the acetate and asuitable plasticizer with a mixture of inert organic solvents, and thensubjecting the impregnation to an alkaline solution to substantiallycompletely precipitate the hydra-ted cellulose as an insoluble layerupon the fibrous base. g

4. The method of treating a fibrous base prepared from mitzumata, kodzu,gampi and other similar plants, .which comprises impregnating the basewith. a solution of cellulose acetate, drying the impregnation, and

the impre ation tothe action of an alkalinesolut on to regenerate thecellulose as an insoluble body upon the fibrous-base.

5. The method of treating a fibrous base prepared from mitzumata, kodzu,gampi and other similarplants, which comprises makingimprintations'thereon, im regnating the fibrous base with a solutionocellulose acetate, and then subjecting the impregnation to the action ofan alkaline solution to regeneratethe cellulose as an insolubledeposition upon the fibrous base.

6. The method of roducing a container for edible products, wfiichcomprises forming a sheet of fibrous material prepared. from mitzumata,kodzu, gampi and other similar plants into a tube, impregnating saidtube with a cellulose derivative, a solution of which is prepared bydissolving in inert organic solvents, and then regeneratingthe'cellulose as an insoluble deposition upon the fibrous base.

7. The method of producing a container for edible products whichcomprises forming a sheet of fibrous material prepared from mitzumata,kodzu, gampi and other similar plants into a tube, making imprintationson said tube, impregnating said tube with a cellulose derivative, asolution of which is prepared by dissolving in inert organic solvents,and then regenerating the cellulose body lags an insoluble depositionupon the fibrous ase.

8. The method of producing a container for edibleproducts, whichcomprises iorming a sheet of fibrous material into a tube, im-

. soluble deposition upon the fibrous base.

ing the end of the tube to form a closure therefor, permitting the tubeto dry, and then regenerating the cellulose. as oan insoluble body uponthe fibrous base.

9. The method of producing a container for edible products, whichcomprises forming a-sheet of fibrous material into a tube, im-

pregnating said tube with a soluble cellulose ester, twistin the end ofthe tube to form a closure there or, permitting the tube to dry, andthen regenerating the cellulose as an in- '10. The method of producing acontainer for edible products, which comprises forming a sheet offibrous material into a tube,

impregnating the tube with a solution of cellulose acetate, twisting theend of the tube to form a closure therefor, permitting the tube to dry,and then subjecting the tube to the action of an alkaline solution toregenerate the cellulose as an insolubledeposition upon the fibrousbase.

11. The method of producing a casing for meat products, which comprisesforming a sheetof fibrousmaterial prepared from mitzumata, kodzu, gampiand other similar plants into a tube, applying identifying marks uponsaid tube, impregnating said tube with a solution of cellulose ester,twisting the end of the tube to close it, drying the tube, and thenregenerating the cellulose as an insoluble-deposit upon the fibrousmaterial.

12. The method of. producing a fabric suitable for use as a covering foredible products, which comprises impregnating a sheet of fibrousmaterial prepared from mitzumata, kodzu, gampi and other similar plantswith a solution ofcellulose acetate, drying said sheet, and regeneratingthe cellulose as an insoluble deposition upon said sheet.

13. The method of producing a casing suitable for use as a covering foredible products, which comprises impregnating a sheet of fibrousmaterial prepared from mitzumata, kodzu, gampi and other similar plantswith a solution of cellulose acetate and a suitable plasticizer to forma flexible transparent material unaffected by water.

14. The method of producing a fabric suitable for use as a covering foredible products, which comprises impregnating a sheet of fibrousmaterial prepared from mitzumata, kodzu, gampi and other similarplantswith a solution of cellulose acetate and a suitable plasticizer toform a flexible translucent material, andregenerating the cellulose asan insoluble deposit-ion upon said base.

15. The method of producing a container for edible products, whichcomprises impregnating a sheet of fibrous material with a solution of acellulose derivative in inert organic solvents, forming the sheet into atube, said im re nating and forming being performed in ith er order,twisting one end of the tube to closethe same, drylng the impregnatedtube, and then regenerating-the cellulose as an insoluble deposit uponthe fibrous base.

16. The method of producing a container for edible products, whichcomprises impregnating a sheet of fibrous material with a solution ofcellulose acetate, forming the sheet into a tube, said impregnating andforming being performed in either order,

twisting one end of the tubeto close the same, drying'the impregnatedtube, and then regenerating the cellulose asan insoluble deposit uponthe fibrous -base.

17 As an article of manufacture, a casing for food products comprising afibrous base prepared from mitzumata, kodzu, gampi and other similarplants and having thereon 20 a deposit of regenerated cellulose preparedfrom de-esterified acetated cellulose.

18. As an article of manufacture, a casingfor food products comprising afibrous base prepared from mitzumata kodzu, gampi and other similarplants and having thereon a deposit of regenerated cellulose obtainedfrom de-esterified acetylated cellulose, upon v and in which is apermanent imprintation.

19. As an article of manufacture, a casing for food products comprisinga branded fibrous base prepared from mitzumata, kodzu, gampi and othersimilar plants and having thereon a deposit of regenerated celluloseprepared from de-esterified acetated cellulose.

- 20. A method of producing a container for edible purposes containingno nitrogenous components comprising forming a sheet of. fibrousmaterial into substantially tubular 40 form impre 'ating said tube withcellulose acetate in so ution in a non-aqueous solvent, de-esterifyingthe cellulose acetate by ways now known until substantially all of theacetic acid radical has been removed therefrom, finally treating)thematerial in a par- 1 aflin hydrocarbon ath, substantially as hereinset forth. I

21. A method for producing a casing for meat products which istranslucent and nongutrescible, comprising forming a sheet of brousmaterial prepared from mitzumata, kodzu, gampi or other similar plantsinto a tubular structure, applying identifying marks upon said tube,impregnating the mass A with cellulose acetate in solution,substantially de-esterif ing the cellulose, acetate to 7 form an insolube depos1t a'sherein set forth.

In testimony whereof I have aflixed my signature.

so LEO A. GOODMAN. V

